1. Field of the Invention
The invention relates to a method of processing image data stored on a memory for rendering an image on a device. The invention relates more particularly to a method of processing image data for printing an image on a print engine or for viewing an image on a display device. The invention relates further to a method of processing image data comprising transformation of the image such as rotation or symmetry operation (mirroring).
2. Discussion of the Related Art
A method of processing image data stored on a memory for rendering an image on a device is known. In particular, a method is known for rotating and rasterizing image data for printing purposes. The image data representing the image to be printed is written onto a Random Access Memory (RAM) and is divided into a number of blocks. The data within each block is rotated and the location of each of the block in the memory is rotated with respect to the original image. The rotated image data is then rasterized and transmitted to a print engine. With the known method, however, difficulties are encountered when the image to be processed is having a file size larger than the RAM space allocated for storing image data. Even when the image data is divided into portions for processing, the portions having a size inferior to the RAM space allocated for storing image data, problems remain. For example, after rotation of a portion, it may happen that that the rotated image data portion comprises truncated data lines. It makes advance image processing, such as halftoning by error diffusion dither or scaling by area mapping, cumbersome.